Reggie Bush will undergo more tests on his injured left leg when the team returns to New Orleans early Tuesday morning.
Early reports indicate that Bush has a broken leg but could return in the second half of the season.
Bush was injured in the fourth quarter of Monday night's victory in San Francisco when he was caught at the bottom of a pileup following his muffed punt return.
He was carried off the field and driven on a cart to the locker room. He was seen on crutches after the game, and the Saints have not released the results of x-rays taken at the stadium.
The Saints already have three backs on injured reserve, having lost RB Lynell Hamilton, RB PJ Hill and FB Marcus Mailei in preseason.
RB Chris Ivory, an undrafted rookie standout in preseason, is out at least another week with and MCL injured suffered in the preseason finale.
Pierre Thomas and DeShawn Wynn are the only healthy runningbacks on the roster, though fullback Heath Evans is versatile and experienced running the ball. Evans has 162 career rushing attempts and four rushing touchdowns in the past nine seasons, and hasn't lost a fumble since 2006.
RB Ladell Betts, with the Saints during preseason, remains a free agent. He was released by the Saints on September 3rd.